There are few well-controlled studies investigating the impact of disinfectant wipes in a clinical setting compared with standard methods. A study from a group of researchers in Cardiff shows that one-step cleaning and disinfectant wipes are more effective than two-step detergent and chlorine solution cleaning / disinfection in removing microbial contamination from hospital surfaces.
The double cross-over study was performed on two wards with an identical layout in Cardiff, Wales. The wards received either standard cleaning / disinfection (two-step detergent cleaning followed by chlorine solution disinfection) or disinfectant wipes (one-step cleaning and disinfectant wipes that produce peracetic acid and hydrogen peroxide when activated by water). The methods were allocated to sequential 3-months blocks so that each ward crossed over between the two cleaning / disinfection approaches, along with a baseline period and washout periods. A training programme for all staff involved with cleaning was delivered before both the standing cleaning / disinfection and disinfectant wipe phases. Weekly samples were collected from 11 surfaces over the course of the study, and ATP was used to measure surface cleanliness.
The introduction of training alone improved the efficacy of standard cleaning and disinfection, resulting in a reduction in colony counts, ATP score, and the presence of indicator organisms. The introduction of wipes demonstrated an incremental benefit over training and standard methods, resulting in a significant reduction in total aerobic count, total anaerobic count, and ATP score compared with baseline; the overall reduction in aerobic count was significantly greater for wipes compared with detergent and chlorine solution. Furthermore, the reintroduction of standard cleaning and disinfection was associated with the counts increasing significantly on many of the items.
The incremental benefit of wipes over training and standard methods is best illustrated by trends in indicator organisms (see Figure). Here, the number of indicator organisms decreased as a result of training and standard methods, but decreased following the implementation of disinfectant wipes. The reduction of antibiotic-resistant Gram-negative bacteria (including ESBLs and CRE) was the most marked.
This paper illustrates both the value of training to improve the standards of conventional cleaning and disinfection, and the incremental value of introducing disinfectant wipes. The disinfectant wipes provided a one-step cleaning and disinfection process that was easier and more effective that a two-step cleaning then disinfection process involving detergent and chorine solution. Although the study was not designed to evaluate any clinical outcomes, the reduction in microbial contamination associated with the introduction of disinfectant wipes, especially contamination with multidrug-resistant Gram-negative bacteria, reduces risk in the clinical setting.
A new study from Jordan has reinforced that cross-resistance between biocides and antibiotics doesn't seem to be a problem. The study found that although multidrug-resistant E. coli were commonly identified from the environment in both hospital and community settings, there was no evidence of cross-resistance between antibiotics and biocides, and all E. coli were susceptible to in-use concentrations of biocides.
21 of 430 environmental samples from two hospitals and 10 homes grew E. coli. Almost half of the isolates were multidrug-resistant, and two thirds were ESBL-producers by phenotype. Surprisingly, there was no difference in the rate of ESBL-producers between hospital and community isolates. Also, the MIC of biocides (including ethanol, chloroxylenol, cetrimide and iodine) were all below in-use concentrations, and similar between community and hospital isolates. Perhaps most importantly, there was no association between antibiotic and biocide susceptibility.
The potential association between biocide and antibiotic resistance has been reviewed in detail before. The European Union produced a report in 2009 concluding that there was limited evidence of biocide and antibiotic cross-resistance. This is because the mechanisms of action of antibiotics and biocides are fundamentally different. Antibiotics tend to have a very specific target, in interrupting the metabolism of bacterial cells, whereas biocides tend to have multiple physical targets and do not rely on interrupting metabolism to be effective. We need to keep an eye on the potential for cross-resistance between biocides and antibiotics - but for now, it is not a problem.
Our clinical team spent some time at ECCMID in Madrid last week, and have summarised some of the key updates from our point of view.
We hope you find this summary useful - please feel free to get in touch if you have any questions!